Current Limitation - Santerno DCREG2 Series User Manual

DCREG2
DCREG4
6.4

CURRENT LIMITATION

The parameters ranging from P050 to P062 variably control the max. current to be supplied to the load.
The figure below shows a possible programming for current limit I lim A(B) depending on speed n and
resulting from the combination of the different configuring modes. The figure refers to converter DCREG4;
the parameters in brackets relate to bridge B.
I lim A(B)
k • P050(51)
k • P052(53)
k • P055
n
0
As the figure shows, in the calculation for the current limit, the major value which all other parameters are
related to is the k one, equal to product C000•Imax[T2] standing for the rate of motor C000 nominal
current less any trimmer hardware limitation (IMAX[T2]). As we discussed above, for the drive normal use,
the IMAX[T2] value is to be at 100%, i.e. the Status page must not display warning A002 (Imax [T2] <
100%). Therefore, the parameters shown in the figure represent a value per cent of motor C000 rated
current.
1st Mode: Limit independent of speed
The current limit may be set at P050(51) rate of the motor nominal current.
2nd Mode: Two-value limit depending on speed.
The current limit may be defined as a simple two-value function, i.e. two different P050(51) and P052(53)
rates. They are selected whether speed is respectively higher or lower than P054 rate of P010 max.
speed.
3rd Mode: Limit with hyperbolic trend depending on speed.
The current limit may be defined hyperbolically depending on speed:
c

I lim A ( B )

n
In the formula above, n
constant for inverse proportionality.
In the latter mode, you need to program P056 rate for the max. speed enabling the hyperbolic step, P057
rate for the max. speed disabling the hyperbolic step and P055 rate for the motor nominal current at the
end of the hyperbolic step, provided that the motor nominal current rate at the beginning of the hyperbolic
step corresponds to P050(51) value.
P010 • P054
P010 • P056
n
0
is the max. speed rate of the hyperbole vertical asymptote, whereas c is the
0
P010 • P057
15P0059B3
USER MANUAL
(k=C000 • Imax[T2])
n
P010
97/200